Joe Belfiore, vice president of the operating system group at Microsoft, holds a pair of mobile phones featuring the new Windows 8.1 operating system during the company's "build" conference in San Francisco, California April 2, 2014.
REUTERS/Robert Galbraith

Nokia launched three Lumia smartphones to be run on the Windows Phone 8.1 at the San Francisco developer conference Build 2014. Nokia decided to be budget-friendly with Lumia 635. It also launched Lumia 630 with dual SIM and Lumia 930. The stylish looking phones will run on Microsoft's new operating software Windows Phone 8.1. Software analyst Michael Muchmore managed to have a first-hand look at the latest operating software. Here are some key points.

Start Screen

The start screen of the Windows Phone 8.1 comes with three columns in place of two. A user can keep an image of their choice on the background of the transparent tiles. The three-column feature goes well with most Windows phones which generally come with wider screens than Apple iPhones. There are some "interesting" options in terms of the looks of the lock screen.

Cortana

Cortana, which is a digital voice assistant, must be the most innovative entry in Windows Phone 8.1. This is Microsoft's answer to its arch rival Apple. Even though Cortana has only one voice, there are things which she can do and Siri cannot. Cortana understands not only the voice of a user but also the written texts. This is a "welcome development" which replaced Windows Phone's search function.

App Store

The app store is redesigned in the Windows Phone 8.1. The development works better because it takes a user to relevant apps much faster than its earlier version. In this era when we spend a lot of time to wade through irrelevant information, this is a fine update.

Action Center

More consider the Action Center more relevant an update than all other improved features in the Windows Phone 8.1. Users can get to the most significant notifications and settings with just a swipe. The connection signal, battery life and time can be viewed with a swipe while staying on any other screen. This was not there in its predecessor.

The Senses

The sensing capabilities are another new addition to the Windows Phone 8.1. A user can see application and data usage with Data Sense. Wi-Fi Sense assists users to connect to free hotspots automatically. Users can decide storage destinations for photos, videos and music. Battery Saver helps users control activities to enhance battery life.